KR100778592B1 - Lubrication structure of camshaft with variable valve timing - Google Patents

Abstract

The present invention forms an advance hole of the cam shaft to which the engine oil is supplied close to the sprocket of the variable valve timing to compensate oil pressure and weak lubricity of the advance side at the initial start of the vehicle, and prevents damage to the journal portion of the cam shaft. To this end, the present invention, the one end of the cam shaft is inserted into the CVVT (Continuously Variable Valve Timing) provided with a sprocket, and a true angle formed in the inner side of the cam shaft body in a position adjacent to the sprocket hall; A crust hole horizontally spaced outward from the position where the true hole is formed and having a crust flow path formed inside the cam shaft body; And a cam cap having a sliding surface formed on the outer side of the advance hole and the perceptual hole formed in the cam shaft to be installed in close contact with the cam shaft on the cylinder head, between the cam shaft and the sprocket when the engine is idle or at low speed rotation. It relates to a lubrication structure of a cam shaft with a variable valve timing, characterized in that the branch flow path is formed on the cam cap so that the progressive-side lubrication performance can be improved with lubrication reduction.

Description

Structure of Continuously Variable Valve Timing of cam shaft lubrication

1 is a view showing a general variable valve timing device.

2 is a view showing a lubrication structure of a cam shaft provided with a variable valve timing according to the present invention.

Figure 3 is an operating state diagram by the lubrication structure of the cam shaft with a variable valve timing according to the present invention.

* Description of the symbols for the main parts of the drawings *

10: variable valve timing 20: fixed ball

100: cam shaft 112: angle hole

122: tectonic hole 200: cam cap

210: branch flow path 212: through hole

The present invention forms the advance hole of the cam shaft to which the engine oil is supplied close to the sprocket of the variable valve timing to compensate for the oil pressure and weak lubrication of the advance side at the initial start of the vehicle, and to prevent damage to the journal portion of the cam shaft. The lubrication structure of the camshaft provided with the variable valve timing which can be prevented.

In general, in order to increase the engine efficiency of the vehicle, it is necessary to change the opening and closing timing of the valve at the high speed and the low speed rotation of the engine according to the driving conditions of the vehicle.

In particular, the opening and closing of the intake valve is a factor that greatly affects the filling efficiency. If the intake valve is opened early, the valve overlap period becomes longer, and the volume efficiency increases because the intake and exhaust inertia flow can be sufficiently used at high speed, but remains at low speed. Increasing the amount of gas tends to decrease volumetric efficiency and increase HC emissions.

In order to solve this problem, a method for varying the opening and closing timing of the intake valve is continuously variable valve timing (CVVT), and the continuous variable valve duration timing is an oil pump and an oil control valve (OCV). : Oil-Flow Control Valve) and oil circuit for advancing or retarding phase angle of intake camshaft by hydraulic pressure.

1 is a view illustrating a general variable valve timing apparatus.

Referring to FIG. 1, the oil pressure supplied from the oil pump (not shown) by the oil control valve (OCV) 2 is transferred to the advance path a or the crust flow path b of the continuously variable valve timing 3. By supplying, the phase of the camshaft 4 is changed and it is comprised so that a valve timing may be adjusted.

The oil supplied to the cam shaft 3 installed at the conventional variable valve timing as described above is supplied from a cylinder block (not shown), and the vehicle is supplied through the crust flow path b at the time of cold start idle, and thus the crust is supplied. The oil pressure of the side is formed.

However, since the oil supplied through the inlet flow path (a) is weak, an oil film is not formed, and thus a problem arises in that the A part is fixed by friction during operation.

In addition, when a chain (not shown) is driven and driven by a sprocket provided at the continuously variable valve timing 3, a load is applied to the cam shaft 4 according to the driving, so that when the lubricating film is not formed in the A portion, This caused a problem that could cause damage to the camshaft 4 and damage to the engine.

The present invention has been made to solve the above problems, and an object thereof is to provide a lubrication structure of a cam shaft with a variable valve timing capable of smoothly lubricating the cam shaft during vehicle cold start or idling. .

In order to achieve the above object, the lubrication structure of the cam shaft provided with the variable valve timing according to the present invention includes one end of the cam shaft being inserted into a variable valve timing (CVVT) provided with a sprocket, An advance hole formed at an adjacent position with an advance passage formed inside the cam shaft body; A crust hole horizontally spaced outward from the position where the true hole is formed and having a crust flow path formed inside the cam shaft body; And a cam cap having a sliding surface formed on the outer side of the advance hole and the perceptual hole formed in the cam shaft to be installed in close contact with the cam shaft on the cylinder head, between the cam shaft and the sprocket when the engine is in an idle state or at a low speed rotation. The branched flow path is formed on the cam cap so that the progressive-side lubrication performance can be improved with lubrication reduction.

One end of the branch flow passage is formed to extend inwardly of the cam cam body having a sliding surface in communication with the crust hole, and the other end is opened to the area between the sprocket and the advance hole to communicate with the cam shaft body.

The branch flow path is formed such that a through hole penetrated toward the place where the sprocket is located is provided with a fixing ball inserted into the through hole to prevent leakage of oil supplied to the branch flow path.

The branch flow path is formed to have a diameter smaller than the diameter of the advance hole or the earth hole.

A preferred embodiment of the lubrication structure of the camshaft provided with the variable valve timing according to the present invention as described above will be described in detail with reference to the drawings.

Figure 2 is a view showing a lubrication structure of the cam shaft with a variable valve timing according to the present invention, Figure 3 is an operating state diagram by the lubrication structure of a cam shaft with a variable valve timing according to the present invention.

Referring to FIG. 2, one end of the cam shaft 100 is inserted into a variable valve timing 10 (CVVT) provided with a sprocket 12, and is positioned at a position adjacent to the sprocket 12. An advance hole 112 in which an advance passage 110 is formed inside the cam shaft body 101; A perceptual hole 122 horizontally spaced outward from the position where the progressive hole 112 is formed, and having a perceptual flow path 120 formed inside the cam shaft body; And a cam cap 200 having a sliding surface formed on the outside of the advance hole 112 and the perceptual hole 122 formed in the cam shaft 100 so that the cam shaft 100 is installed in close contact with the cylinder head. The branched flow path 210 is formed on the cam cap 200 to improve the lubrication performance of the advancing side with the reduction of the lubrication between the cam shaft 100 and the sprocket 12 during the idle state or the low speed rotation. do.

That is, the camshaft 100 which is connected to the sprocket 12 when the camshaft 100 is driven is the advance hole 112 in which the advance passage 110 is formed and the perception hole 122 in which the perceptual passage 120 is formed. In order to achieve a lubrication balance due to the load applied thereto, the crust passage 120 having the crust hole 122 is positioned as far as possible from the position where the CVVT (Continuously Variable Valve Timing) is located. The cam shaft body 101 is configured to be located in the area where the surface contact is made and sliding.

Branch flow path 210 according to the present invention is one end is in communication with the crust hole 122 is formed extending into the cam cam body 201 having a sliding surface and the other end is the area between the sprocket 12 and the true hole 112 It is configured to open in communication with the cam shaft body 101.

The branch passage 210 is formed with a through hole 212 penetrated toward the place where the sprocket 12 is located, and is inserted into the through hole 212 to prevent leakage of oil supplied to the branch passage 210. The fixed ball 20 is configured to be provided.

The branch flow path 210 is formed to have a diameter smaller than the diameter of the advance hole 112 or the perceptual hole 122.

The operation state of the lubrication structure of the camshaft provided with the variable valve timing by this invention as above is demonstrated with reference to drawings.

2 to 3, when the speed of the vehicle is reduced or the engine (not shown) is operated in the idle state of the cold start (oil temperature of 5 ° C. or less), the variable valve timing (CVVT: Oil supply to the Continuously Variable Valve Timing) is supplied through the crust passage 120 and the oil supplied to the crust passage 120 is discharged to the crust hole 122 and the cam cam body is in surface contact with the cam shaft body 101. A lubricating film and oil pressure are formed between the 201.

At this time, since the oil film is not formed on the part where the sliding surface of the cam cap body 201 on the true side and the cam shaft body 101 are in surface contact with each other, the branch path 210 passes through the branch flow path 210. Part of the supplied oil is supplied as shown by the dotted line in the figure.

The oil supplied to the crust hole 122 is supplied to the other side of the branch flow path 120, but as shown in the drawing, an oil film is formed on the sliding surface between the sprocket 12 and the recess hole 112 to form an oil film. Reduce friction.

In addition, the lubrication film is not destroyed by the load applied to the cam shaft 100 by the chain (not shown) connected to the sprocket 12, and lubrication is imposed so as to prevent the destruction of the cam shaft 100 or damage to the engine. do.

The inner diameter (d) of the branch flow path (120) is formed smaller than the inner diameter (D) of the true hole (112) or the tectonic hole (122) to minimize the hydraulic loss inside the tectonic flow path (120) and the variable valve timing This prevents the functional degradation.

The through hole 212 formed in the branch flow path 120 is provided with a fixed ball 20 made of steel, and the through hole 212 opened by the fixed ball 20 after forming the branch flow path 120. To prevent the branch passage 120 from being stably lubricated.

On the other hand, the present invention can be variously modified by those skilled in the art without departing from the gist of the invention.

As described above, the lubrication structure of the camshaft provided with the variable valve timing according to the present invention has the effect of improving the lubricity on the forward side at the initial start of the vehicle.

In addition, by maintaining the existing variable valve timing (CVVT), lubrication is provided on the incidence side where lubrication is poor at initial start-up or idle time, which prevents damage to the cam journal or the engine, and prevents seizure due to lubrication film destruction. It has an effect.

Claims (4)

One end of the cam shaft 100 is inserted into the variable valve timing 10 (CVVT) provided with the sprocket 12, and the inner side of the cam shaft body 101 is positioned adjacent to the sprocket 12. An inlet hole 112 formed with an inlet path 110; A crust hole 122 horizontally spaced outward from a position at which the true hole 112 is formed so that a crust flow path 120 is formed inside the cam shaft body; And Cam cam 200 is provided on the outer side of the true hole 112 and the tectonic hole 122 formed in the cam shaft 100 is provided with a sliding surface formed so that the cam shaft 100 is in close contact with the cylinder head engine A cam cam body having a sliding surface formed at one end thereof in communication with the crust hole 122 so that the lubrication performance of the advancing side can be improved while the lubrication between the cam shaft 100 and the sprocket 12 is reduced in the idle state or at a low speed rotation. Variable valve timing, characterized in that the branch flow path 210 is formed extending into the inside of the 201 and the other end is opened to the area between the sprocket 12 and the progressive hole 112 in communication with the cam shaft body 101. Lubrication structure of the cam shaft provided. delete The method of claim 1, The branch passage 210 is formed with a through hole 212 penetrated toward the place where the sprocket 12 is located, and is inserted into the through hole 212 to prevent leakage of oil supplied to the branch passage 210. Lubrication structure of the cam shaft with a variable valve timing, characterized in that the fixed ball 20 is provided. The method of claim 1, The branch flow path 210 is a lubrication structure of a cam shaft provided with a variable valve timing, characterized in that formed to have a diameter smaller than the diameter of the progressive hole 112 or the tectonic hole (122).

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